Radiation-pyrometer.



C. B. THWING.

RADIATION PYROMETER LlCATiON FILED MAY4 19 1,232,408. I I Patented July 3,1917.

STATES PATENT OFFICE.

CHARLES ."B. THWING, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THWING INSTRUMENT COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

- RADIATION-PYROMETER.

certain Improvements in Radiation-Pyrometers, of whichthe following is a specification.

One object of my invention is to provide a form of radiation pyrometer which, by

reason of its construction and arrangement of parts, shall be relatively inexpenslve to manufacture and durable under operatingconditions, the invention contemplating a relatively simple construction which, while giving accurate results, can be made of comparatively cheap materials.

These objects and other advantageous ends I attain as hereinafter set' forth, reference being had to the accompanying drawings, in which Figure 1 is a section illustrating a radiation pyrometer constructed according to my invention, and Fig. 2 is a fragmentary section illustrating a modification of my invention.

In the above drawings, 1 represents a portion of the wall or arch of a furnace, or of a brick or other kiln, having an opening in which is mounted a mufile 2. This latter preferably has the form of a hollow refractory cylinder flanged at one end and closed at its opposite end, its length being such that said closed end projects into the kiln, furnace, etc., for some distance beyond the inner face of the wall 1.

A suitable number of refractory blocks 3, 3 and 3 should be mounted outside of the mufile whose outer end as well as said blocks I inclose in a suitable metallic protective casing 5. Each of the blocks above mentioned is perforated and through them extend the elements 6 and 7 of the pyrometer or whatever other temperature responsive device is employed, this being shown in the present instance as inclosed within a thin refractory tube 8 supported by the blocks 3,

' 3 and 3 and closed at its inner end, which terminates in the mufiie outside the plane of the inner face of the wall 1.

The thermo elements 6 and 7 or whatever other device is designed to be acted on by the heat of the kiln in order to give an indication of the temperature of the same, likewise terminate within the muflle between the planes of the inner and outer faces of the wall 1, and it will be noted that the tube Specification of Letters Patent.

Patented July 3, 191 '7.

Application filed May 4, 1914. Serial No. 836,341.

8, although preferably employed for the protection of this part ofthe instrument, may be omitted if found advisable without departing from my invention.

A fourth block 9, preferably fixed to a metallic cap 10, is designed to fit over the outer open end of the protective tube-8 and the thermo elements, so asto maintain the temperature of their cold ends substantially constant, being provided with a handle 11 whereby it may be conveniently manipulated.

, While the inner end of the mufiie 2 should properly project into the furnace or kiln beyond the inner face of the wall 1, it is, of course, possible that it might be flush with the inner face of the wall or might even be terminated below the same, as shown at 2 in Fig. 2, but such constructions do not give as satisfactory results as that illustrated.

With a mufile whose closed inner end projects a definite distance within or beyond the inner surface of the kiln wall 1 it will be understood that said end is exposed to the kiln heat which, being radiated from its inner surface, affects the thermo elements 67 in the well known manner to an amount which is a function of the temperature of the kiln. Owing to the fact that the temperature to which the thermo elements are exposed is, therefore, considerably lower than that of the kiln or furnace, it is permissible' to make them of inexpensive and yet durable materials. I

Since the convection curents within-the mufile are relatively slight and since the amount of heat, radiated from the muflie walls immediately adjacent the inner ends of the thermo elements 6'7, or other temperature responsive device, is also practically negligible, it is obvious that said device is affected by and raised to a temperature which is practically dependent upon the amount of heat radiated from the heated Inner end of the mufl'le 2, and hence directly related to the temperature of the kiln. In

, order, therefore, to obtain correct and accu-- the interior of the kiln would affect the thermo-element directly instead of through out departing from my invention said end may in some cases be open'as indicated in Fig. 2, in which case, the radiations from the end of the muflie, said couple in any case being spaced away from the walls of said muflle. It is, therefore, to be noted that the thermo element is mounted within a mufile so as to be some distance from its adjacent walls and that said muflle is placed in the wall of the kiln or furnace in such position that the thermo elements lie to the rear 01' the plane of the inner surface of said wall.

I claim:

1. The combination in a radiation pyrom-. eter of a hollow refractory structure'forming a muflie; a refractory block mounted on the muffle; a pair of elements constituting a thermo-couple mounted in the block with its hot end extending part, way int?) said mufile so as to lie within a relatively cool portion thereof in position to receive heat radiated from a materially hotter portion.

2. The'combination in a radiation pyrometerof a hollow refractory structure forming a muffle; a refractory block mounted on the mufiie; a pair of elements constituting a thermo-couple mounted in the block with its hot end'extending into the mufflein-position to be acted on by-heat. radiated from the inner walls thereof; with a cap for inclosing and maintaining substantially In any case, i

" exposed to heat; a muflie mounted in sald constant the temperature of the cold. end of the thermo-couple.

3. The combination of a refractorywall wall with its inner end projecting beyond the inner face thereof; and a thermo-co'uple mounted to extend in the outer part only ofsaid muffle in position to be acted on by heat radiated from the inner surface or that part thereof which projects inside the walls.

4. The combination of a refractory wall exposed to a source of heat; a muffle extending through said wall and having a closed end projecting beyond the inner face thereof; with a thermo-couple extending-v into said muffle bnt terminating outside theplane of the inner face of the wall in position to be affected by heat radiated from the inner surface of the closed end-of the muifle.

5. The combinationv of a muflle in the form of an elongated hollow structure of refractory material closed at one end; a casing mounted at the opposite end of said muflie; a thermo-couple mounted in the cas- -having a refractory wall; a muflle in said wall; and a pyrometer in the mufile spaced away from the adjacent walls thereof and on the outer side of the plane of the inner surface of the refractory wall.

In testimony whereof, I have signed my name to this specification, in the presence oftwo subscribing witnesses.

CHARLES B. THWING.

Witnessesz WILLIAM E. BRADLEY, Jos. H. 

